Imran Khan has been accused by rivals failing to file tax returns and losing
money raised for his cancer hospital on international property markets.

In the surest sign yet that Mr Khan, the former cricket captain turned politician, is being taken seriously by his rivals ahead of elections expected early next year, two senior opposition figures have questioned his reputation as a squeaky clean anti-corruption campaigner.

He denies the allegations.

Mr Khan's party has stunned pundits and established politicians by drawing huge crowds of predominantly young voters energised by his promises to rid the country of a corruption-riddled elite.

This week Chaudhry Nisar Ali Khan, a senior leader of Pakistan's main opposition PML-N party, claimed Mr Khan had made millions of rupees during the past 30 years but had not filed any tax returns until 2003.

It followed allegations made earlier by Khwaja Asif, from the same party, that millions of dollars raised for Mr Khan's cancer hospital – built in memory of his mother – had been lost as international property markets plunged.